diff --git a/classes/config.php b/classes/config.php
index afb182440..a4a42a60a 100644
--- a/classes/config.php
+++ b/classes/config.php
@@ -524,8 +524,8 @@ class Config {
 				array_push($errors, "Please don't run this script as root.");
 			}
 
-			if (version_compare(PHP_VERSION, '7.1.0', '<')) {
-				array_push($errors, "PHP version 7.1.0 or newer required. You're using " . PHP_VERSION . ".");
+			if (version_compare(PHP_VERSION, '7.4.0', '<')) {
+				array_push($errors, "PHP version 7.4.0 or newer required. You're using " . PHP_VERSION . ".");
 			}
 
 			if (!class_exists("UConverter")) {
diff --git a/index.php b/index.php
index b1f3274f3..b7c039d7a 100644
--- a/index.php
+++ b/index.php
@@ -2,8 +2,8 @@
 
 	// we need a separate check here because functions.php might get parsed
 	// incorrectly before 5.3 because of :: syntax.
-	if (version_compare(PHP_VERSION, '7.0.0', '<')) {
-		print "<b>Fatal Error</b>: PHP version 7.0.0 or newer required. You're using " . PHP_VERSION . ".\n";
+	if (version_compare(PHP_VERSION, '7.4.0', '<')) {
+		print "<b>Fatal Error</b>: PHP version 7.4.0 or newer required. You're using " . PHP_VERSION . ".\n";
 		exit;
 	}
 
diff --git a/prefs.php b/prefs.php
index 84d89f914..36641e0f3 100644
--- a/prefs.php
+++ b/prefs.php
@@ -1,4 +1,11 @@
 <?php
+	// we need a separate check here because functions.php might get parsed
+	// incorrectly before 5.3 because of :: syntax.
+	if (version_compare(PHP_VERSION, '7.4.0', '<')) {
+		print "<b>Fatal Error</b>: PHP version 7.4.0 or newer required. You're using " . PHP_VERSION . ".\n";
+		exit;
+	}
+
 	set_include_path(__DIR__ ."/include" . PATH_SEPARATOR .
 		get_include_path());